Automatic screw machine



Fb. 10, 1953 6 R. D. PERRY ET AL AUTOMATIC SCREW MACHINE 4 Sheets-Sheet 1 Filed June 23, 1948 INVENTORS IEOSS BAUNGAPDNER E/CHA JED D- PERRY arm A TTOR/VEYS Feb. 10, 1953 R. D. PERRY ET AL AUTOMATIC SCREW MACHINE 4 Sheets-Sheet 2 Filed June 23, 1948 INVENTORS E055 BA UMGA EDNA-IE 4 76/0111 2w 1)- PERRY ATTORNEYS Feb. 10, 1953 R. D. PERRY ET AL AUTOMATIC SCREW MACHINE 4 Sheets-Sheet 3 Filed June 23, 1948 E Y m m w A V6 r WW3 Y N A? B I a w 0% lllll 0 R Feb. 10, 1953 R. D. PERRY ETAL AUTOMATIC SCIQEW MACHINE 4 Sheets-Sheet 4 Filed June 2", 1948 INVENTOR Patented Feb. 10, 1953 AUTOMATIC s-cnsw MACHINE Richard D. Perry, Elyria, and Ross Baumgardner, Grafton, Ohio, assignors to The Perry-Fay Company, Elyria, Ohio, a corporation of Ohio Application June 23, 1948, Serial No. 34,714

implement the foregoing operations comprises,

generally, a pneumatic piston cylinder assembly having a hydraulic check coupled therewith to restrain the rate of travel of the piston during a portion of the stroke "thereof.

In the application of such mechanism to a screw machine the piston may be coupled with the tool slide, or similar part, to. eiiect the rapid traverse thereof, the hydraulic check attached to the piston to regulate the translation of the tool slide and the valve in the hydraulic unit adjusted to govern the rate of movement, or feed, of the portion of the stroke of the piston that is controlled thereby.

One of the objects of the invention is to provide an organization of hydro-pneumatic transmission mechanisms of the character referred to above for the various operative elements of the machine and to orient such transmissions with each other and with the tool slides, turret, stock feed, stop, and chuck-operating mechanisms to produce the sequential order of operation of the tools in the most efflcacious manner and in the shortest possible time.

To this end the invention contemplates a valve-operating unit for each cylinder assembly in the machine, electric or fluid connections therefor which are arranged to accommodate changes in the order of operation of the devices and instrumentalities associated with the valveoperating units to facilitate modification of the operative movement of each of the units.

Other objects and advantages of the invention reside in the provision of a machinewhich is efiicient of operation, economic of manufacture, reliable of performance, and susceptible of ready alteration for tool change-over operations or new setup assemblies.

Referring to the drawings:

Fig. 1 is a view-in-perspective of the forward side of a screw machine embodying the improved tool-operating mechanisms;

Fig. 2 is a plan view thereof;

Fig. 3 is a diagrammatic view of the tool- 8 Claims. (C1. 29-42) 2 actuating mechanisms and the pneumatic and electrical connections therefor;

Fig. 4 is'a detail view in section of the swinging gauge stop operatingmechanism, the section being taken on a plane indicated by the line 4-4 in Fig. 3; 1r

Fig. 5 is a fragmentary detail showing one modification of the electrical connections in the junction box;

Fig. 6 is a second modification of the electrical connections in the junction box; and

Fig. '7 isa third modification of the electrical connections in the junction box.

Referring first to Fig. 1, .the screw machine chosen herein for the purpose of illustration comprises, generally, a bed [0 having ways H therein, a tool slide 12. a headstock l3 of conventional form, and opposed cross slides 14 and 15. The bed is mounted on legs l6 and the headstock spindle I1 is driven in the customary manner by a motor l8 preferably supported by a bracket secured to the bed ID.

The initial movement of the carriage and cross slides is efiected by independent pneumatic cylinder assemblies, while the final movement or feed cycle thereof is attained through the hydraulic cylinders associated therewith. The valves for the various elements in the machine are actuated through electric or hydraulic control units, the order of operation thereof being determined by the arrangement of the connections between the respective valves. For example, if the sequence of operations demands the actuation of a form tool following the movement of the turret slide the latter may be electrically connected to the valve control unit for the form tool and a switch may be interposed in the line for operation by the-turret slide at the end of theistroke thereof.

In detail the ';electric current is brought to the machine through a conduit 20 (Fig. 3). which leads to a junction box containing bus bars 2!, 22, and 23 connected to the startingqs'witchil for the motor l8 and a second motor 25 for driving a, coolant 'pump 26, The pump is provided with a conduit 21 that leads to a reservoir 28 in the bed of the machine and with a discharge line ,29 that terminates in contiguous relation with the cutting tools inthe cross slides i4 and [5. The bars 2| and 22 are'con-nected to a transformer 3ll whichin turn is coupled with bus bar 3| and terminal block 32 arranged to accommodate the interchangeable assembly of the lines to and from the switches that control the various operating units in the machine.

As illustrated in the exemplary organization of tools, the stock S is fed through the collet in the work-holding spindle ll until the end thereof is brought into abutting engagement with a swinging gauge stop 33. The next step in the operative cycle of the machine requires the closure of the collet upon the bar stock. This operation is effected through the provision of a switch 33 mounted on the gauge 33 and electrically connected to the binding posts F and 8 in the terminal blocks 3| and 32. If desired, jacks may be substituted for the binding posts and the lines may be provided with plugs to facilitate ready manipulation of the connections. One side of a solenoid 31, which is associated with the colletoperating mechanism, is electrically connected to a binding post 8 which actuates a-valve 33 when the switch 34 is closed. The valve 38 controls pressure fluid delivered from a compressor through a conduit 39 to a piston cylinder assembly 40. The piston rod 4| supports a yoke G2 on the outer end thereof which is engaged with a grooved collar 43 connected to a collet draw tube, not shown, in the manner customarily employed in spring chuck operating mechanisms. When the piston rod is extended the collet tube will be retracted, thus closing the chuck upon the stock, and at the same time closing a blocking valve F through which the fluid passes to force the stock outwardly against the gauge stop 33. The fluid displaced from the cylinder 40, during the actuation of the piston, is led through a conduit 44 to a cylinder 45 having a piston therein arranged for engagement with an electric switch 55. connected to the terminals 3 and D in the blocks 3| and 32. Cylinder i5 is equipped with an adjustable :weep" valve of conventional nature which controls the length of the interval during which the piston is in engagement with switch 46. Since the quantity of fluid available from cylinder 40 is limited, the efiect of the. weep valve is to make the closing time ofswitch 46'momentary. One side of the. solenoid 41 is electrically connected to the terminal 3, which operates the piston cylinder assembly 48 and actuates tool slide l2 when the switch 46 is closed. The cylinder 48 is supplied with pressure fluid from a branch line 49 coupledwith the conduit '39. As illustrated, a center drill 50 is mounted in the tool block in the slide l2, though other tools may. be substituted therefor.

The cylinder valving is constructed to efieot the rapid translation of the pistonin the cylinder 48 during the initialmovement.thereoi, .but such translation is retarded by the action'of a. hydraulic plunger 5| before the pistonreaches the end of its stroke. A valve is provided in the hydraulic unit which may beregulated to produce the requisite rateof-feed forthertool controlled therebyi When-the tool slide i2 is advanced to the point "of' final operation,- an adjustable plunger. 52 is brought into engagement with a switch 53' which is connected with terminals E and 4 in the. blocks 3i and 32. The other side of the solenoid 41 is electrically connected to'the terminal 4 whichirevcrses the operation of the piston cylinder assembly, 43,1when the switch 53 is closed. The solenoid control-has two operating positions and continues to: supply fluid to the assembly ls' after the solenoid 61 is -de'energized.' Subsequent momentary energization of the other side of solenoid 41 is required to cause actuation of the piston to the opposite end of the cylinder;

The forming tool slide and cut-off slide cylinders GI and are actuated in the same manner as the turret slide l2, all three slides starting at the same time by bridging the respective leads from the solenoids and 54 to terminals i23, all of which are actuated by closing the switch 46, as described above. The slides 6i and 55 are supplied with pressure fluid from a branch line 56 coupled with main pressure-line 39. These slides are used for forming and cutting off the finished piece, the cutting feed being controlled in the same manner as that of the slide 12 described above. The return movement of these slides is effected by contacting switches 18 and 59 at the finish of the work stroke, operating solenoids 54 and G0, and reversing the action of cylinders 55 and 61. The switches and 59 are constructed to serve as positive stops for the tool slides and are preferably provided with micrometer heads to facilitate the accurate duplication of parts.

Independent operation of any or the tool slides may be accomplished by bridging a pilot valve switch in the circuit of the slide. in the manner employed in connection with the switch 45, wherein the exhaust fluid fromthe cylinder effects the actuation of the piston in another cylinder.

The cylinder 55 is provided with conduit 64 that leads to a cylinder 65 (Fig.4). having a piston therein whichsupports a rack 55 entrained with a pinion 61 mounted on a shaft 63 that supports the swinging gauge stop 33. When the slide controlled by the cylinder 55 is actuated and. starts its forward motion pressure fluid passes through the branch line 56, through one side of a solenoid valve assembly 54 to the cylinder 55, and through'a conduit 64. to a cylinder $5,'causing retraction of the gauge stop 33. The reverse actionof the gauge stop 33 is effected by pressure fluid passed from;the other side of the solenoid valve assembly 54 through a conduit N54 to the opposed end of the cylinder 65 and also to the opposed endof: cylinder 55 to efiect the reversal thereof.

With the return stroke of the cut-oil slide M, the exhaust fluid from the cylinder 55 is carried in a conduit I2 to a cylinder H, closing momentarily a. switch I10 connected to the terminals T and C. The solenoid 31 on the cylinder 40 is electrically connected to the terminal I, which operates the cylinder 40 upon closure of the switch 110. to actuate the rod M and effect the release of the chuck or collet in the spindle head ll.

When the piston rod '4! reaches the end of its stroke'the push bar l6 thereon will engage a valve and permit the passage of pressure fluid from the conduit 16, coupled with the com pressor; to a line llithrough a master control valve 18, and to a stock'tube 19. As the fluid enters the tube 19' it will'effect the ejection of the stock through the open collet until the flight thereof is arrested by the gauge stop 33 which has been previously actuated to its operative position by the pressure fluid controlled by the valve assembly;54.

The stock. tube 19 is provided with a coupling fillof a type that may be readily detached to accommodate the reloading operation of the tubes The tubeassembly is further provided with swivelconnections '8! to facilitate rotary adjustments thereofrwhen the bar stock is replenished.

When t e stock engages the switch 34 associated with the stock gauge 33 the operative cycle is completed and the various elements of the machine will follow the pattern of operation heretofore described. Should the nature of the work require modification of the tool set or a change in the order of operation of the tools such change may be readily made by readjustment of the electrical connections in the terminal blocks 3| and 32 and alteration of the feed control plungers El, 51, and 63.

Modified electrical connections on the terminal block 32 are shown in Figs. 5-7 inclusive in which Fig. 5 illustrates the circuit normally provided in the control cabinet when it is desired to energize the tool slide solenoid valve from the collet operating solenoid. This is accomplished by placing an electrical jumper from terminal 8 to terminal 3. With this control arrangement, the tool slide will begin moving into operating position simultaneously with the gripping of the stock by the collet. All other connections both internal and external of the cabinet as shown by the dotted lines remain the same.

Fig. 6 illustrates the modified circuit used to provide a sequence in which a tool slide solenoid valve is connected to the control switch on another tool slide thus causing the first slide to begin operation when the second slide has reached the end of its travel. A jumper is placed between terminals 2 and 4 which allows ener gization of the second tool slide solenoid only upon closing stop switch 53.

By making the connections as shown in Fig. 7,

the tool slide valve solenoid will be energized by the closing of the stop gauge switch resulting from the movement of the stock into tool receiving position whereupon the slide will begin moving into working position immediately after the stock has closed switch 34. In this sequence, a jumper is used from terminal 3 to terminal 8 thus completing the circuit from one operating part to another. A series of four definite operating sequences are illustrated in these drawings, but manifestly, a large number are possible which are not included herein, but are contemplated as being a part of this invention.

It will be recognized that the electric control set may be supplanted by a hydraulic system in which pressure and exhaust fluid controlled by bleed or so-called weep valves are substituted for the solenoid actuated valves and contact switches.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

We claim:

1. In a machine tool embodying a rotatively driven work-holding spindle, a chuck-operating mechanism, av movable gauge stop, and a plurality of reciprocative tool slides, mechanism for the control of the sequential order of operation of the chuck-operating mechanism, gauge stop and tool slides comprising an electric switch on said gauge stop, a fluid-operated piston cylinder assembly interlinked with said chuck-operating mechanism, a solenoid valve therefor electrically connected with said gauge stop switch, fluidoperated piston cylinder assemblies on the tool slides, solenoid valves therefor electrically connected to said chuck-operating solenoid, and fluid-operated means coupled with one of the tool slide piston cylinder assemblies for actuating said gauge stop.

2. In a machine tool embodying a rotatively driven work-holding spindle. a chucking mechanism, a stock feed mechanism, a stock stop and a plurality of tool slides, mechanism for operating said chucking mechanism and stock feed mechanisms, said stop and tool slides in sequential order comprising an electric switch on said stock stop, a pressure fluid piston cylinder assembly connected to said chucking mechanism, a solenoid valve therefor electrically connected to said stock stop, pressure fluid piston cylinder assemblies associated with each of said tool slides. solenoid valves therefor electrically connected to said chucking mechanism solenoid, a fluidoperated stock feed mechanism, a valve therefor operated by said chucking mechanism, and a piston cylinder assembly operated by pressure fluid controlled by the solenoid valves associated with one of the tool slides for actuating said stock stop. I

3. An automatic screw machine comprising a rotatively driven work-holding spindle, a collet therein, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control thereof, a swinging gauge stop, a fluid pressure piston and cylinder for the actuation thereof, an electric switch on said stop operable by engagement of the stock therewith, electric connections between said switch and said solenoid valve, a tool slide, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control of said piston, electric connections between the firstand last-named solenoid valves, and fluid connections for operating the gauge stop piston by the pressure fluid con trolled by the solenoid valve of the tool slide cylinder.

4. An automatic screw machine comprising a rotatively driven work-holding spindle, a collet therein, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control thereof, a gauge stop, an electric switch thereon operable by engagement of the stock therewith, electric connections between said switch and said solenoid valve, a tool slide, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control of said piston, electric connections between the firstand last-named solenoids, a fluid-operated stock feed mechanism, a control valve therefor, and means on the collet actuating piston for the actuation of the stock feed valve.

5. An automatic screw machine comprising a rotatively driven work-holding spindle, a collet therein, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control thereof, a swinging gauge stop, a fluid pressure piston and cylinder for the actuation thereof, an electric switch on said stop operable by engagement of the stock therewith, electric connections between said switch and said solenoid valve, a tool slide, a pressure fluid piston and cylinder for the actuation thereof, a solenoid valve for the control of said piston, electric connections between the firstand last-named solenoid valves, a pair of cross slides, pressure fluid pistons and cylinders for the actuation thereof, solenoid valves for the control thereof, electric connections between the first-named solenoid and accesses the lastsnamed solenoids, 'fluid connectionsfrom one, of the valve assemblies-.ofthecrossslide cylin.-. ders to the gauge stop-cylinder for the actuation thereof, a pressure fluid stock feed mechanism, a valve therefor, and an arm on the collet-operating piston for the actuation thereof.

6. An automatic screw machine comprising a rotatively driven workeholding spindle, a collet therein, a pneumatic piston cylinder assembly for the operation thereof, a solenoid valve thereon, a gauge stop, an electric "switch thereon, said. solenoid valve being connected to said auge stop switch, a tool slide, a pneumatic piston cylinder assembly for the operation thereof, a hydraulic check thereon to retard the movement thereof \vithina portion of the stroke of the tool slide, a solenoid valve on said piston cylinder assembly, a pair of cross slides, pneumatic piston cylinder assemblies for the operation thereof, hydraulic, checks thereon to retard the movement thereof Within a portion of the stroke of said slides, sole:- noid valves on said cross slide piston cylinder assembly connected with the solenoid valve for the collet piston cylinder assembly, and fluid-0perated means controlled by the pressure fluid from one of said cross slide valve assemblies for the actuation of said gauge stop.

7. An automatic screw machine comprising a bed, a work-molding spindle thereon, acollet therein, afluidsoperatedactuating mechanism therefor, a solenoid valve forthe control thereof. cross tool slides on said bed, fluid-operated actuating mechanisms, therefor, solenoid valves for the control thereofnelectrically connected to the solenoid valve for the collet solenoid valve, a longitudinal tool slide on the bed, fluid-actuating mechanism therefor, a solenoid valve for the control thereof electrically connected with the collet and cross slide solenoids a swinging auge stun,

a fluid-operated actuating, mechanism. therefor, anelectrical switch thereon operable by engagement of the stocktherewith, electric connections.

therefor coupled withlsaid solenoids, fluid oonnections between one of said cross slides and the gauge stop, fluid-operating mechanisms foreperating the latter by the fluid displaced from the former, a fluid-operated stock feed mechanism, a control valve therefor and means operable by the collet, and fluid-operated mechanism for the actuation of said valve.

8. In an automatic screw machine embodying fluid-operated tool slides, stock feed, gauge stop and collet actuator, mechanism for the operative control thereof comprising an electric switch associated with the gauge stop, solenoid valves associated with the tool slides and collet actuator, electric connections between said switch and said solenoid valves, fluid-operated means controlled by the movement of one of the cross slides for actuating the gauge stop, and mild-operated means controlled by the movement of the collet actuator for operating the stock feed mechanism.

RICHARD D.. PERRY. ROSS BAUMGARDNER.

REFERENCES CITED The following references are of'record in the file of this patent:

UNITED STATES PATENTS Number Name Date 627,385 Brockieem June 20, 1899 2,148,348 Groeneet a1 Feb. 21, 1939 2,384,809 Bullard et a1 Sept. 18, 1945 2,429,938 Mansfield Oct. 28, 194'? 

